Pattern hatch gets messed up when exporting to DWG

I've created a batten cell and used it for pattern hatching. As you can see in the screenshots something weird is happening with the pattern when exporting the file to dwg format. When the cell is placed as a single cell it doesn't get corrupted.

Maybe someone could please enlighten me about the under-the-hood-process of transforming hatch pattern to dwg format as I would like to know how I could optimize the batten cell for export.

By the way: the same things happen when I try to use batten linestyles. In Microstation everything looks great but after exporting it to dwg the linestyle looks the same as the broken pattern.

Regards
Stephan